A Light box for optical module test is disclosed. The light box is designed to have at least a light source, a beam splitting unit, an optical filtering module and two optical fibers. The optical filtering module is formed with a plurality of filters and arranged between the light source and the beam splitting unit to generate a variety of color temperatures of the light beam from the light source before the light beam enters the beam splitting unit. Thereafter, the light beam is uniformly divided by the beam splitting unit into a first light beam and a second light beam which are transmitted via the optical fibers, respectively, and projected onto a test chart.